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Home / Computer Hardware, Monitors & Peripherals / MQ2 Smoke, Alcohol, Methane, Coal Gas, Hydrogen, Carbon Monoxide, and Combustible Gas Sensor Module

Attributes

Brand -
Category Electronic Components / Maker DIY / Computer Hardware, Monitors & Peripherals
Origin -
Operating Voltage 5V DC
Heating Voltage 5.0V ± 0.1V
Load Resistance Adjustable (20kΩ default)
Heating Resistance 33Ω ± 5%
Sensing Resistance 10kΩ - 60kΩ
Preheat Time 24-48 Hours
Operating Temperature -10°C to 50°C
Output Type Analog (AO) & Digital (DO)
Pin Interface 4-Pin Header (VCC, GND, DO, AO)
PCB Dimensions 32mm x 20mm

5 reviews

A

Anonymous

Mar 29, 2026

Rating: 5/5

Reliable module

Used MQ-5 for LPG detection in a prototype. Very stable output.

A

Anonymous

Feb 12, 2026

Rating: 5/5

Great for Arduino Projects

Works perfectly with my Uno. Calibrated well after 24 hours.

A

Anonymous

Jan 29, 2026

Rating: 4/5

Good sensitivity

Detects smoke well. Wish the potentiometer was easier to adjust.

A

Anonymous

Jan 26, 2026

Rating: 5/5

Exactly as described

Bought the MQ-135 for air quality. Readings are consistent.

A

Anonymous

Jan 18, 2026

Rating: 3/5

Needs patience

Takes a long time to warm up. Make sure you read the datasheet.

5 FAQ

Q: How long before it's accurate?

A: We recommend 24-48 hours initial preheat for stable readings.

Q: Can this run on 3.3V logic?

A: The sensor needs 5V heating, but AO can be read by 3.3V MCUs with caution.

Q: Can MQ-2 detect Carbon Monoxide?

A: MQ-2 is primarily for smoke/LPG. Use MQ-7 for Carbon Monoxide.

Q: Is the DO pin adjustable?

A: Yes, use the onboard potentiometer to set the threshold trigger.

Q: Does it output ppm directly?

A: No, it outputs voltage proportional to concentration. You need to calibrate for ppm.

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